Incinerator



Dec. 29 1964 W. T. S. MONTGOMERY 3 1 3 133 INCINERATOR Filed June 29, 1960 3 Sheets-Sheet l 5e E I 48 3' 3 5 36 58 1o 5 4o 14- 64,62 3". 4 2 lit 74 5- l5 5' 114 A 112 132 2 90 v 106 12s 134 INV EN TOR BY g6 flaw ATTORNEYS Dec. 29, 1964 w. T. S..MONTGOMERY 3,163,133

INCINERATOR Filed June 29, 1960 3 Sheets-Sheet 2 4, INVENTOR .80 William T61 Mont r omaj I BY 97% 4 5 w.

ATTORNEYS Dec. 29, 1964 w. T. s. MONTGOMERY 3,163,133

INCINERATOR 3 Sheets-Sheet 3 Filed June 29, 3.960

INVENTOR William T S.Mo1 g01rw13 BY i fi f ATTORNEYS United States Patent 3,163,133 INQENERATGR Wiilimn T. S. Montgomery, .lacksonville, Fla assignor to Jacksonville Blow Pipe Company, Eacltsonviile, Fla, a corporation of Florida Filed June 29, 1966, Ser. No. 359,503 14- Clairns. (Cl. 119-18) This invention relates to incinerators for burning fuels and more particularly is directed to a furnace for burning relatively small particles of wood, such as wood bark, sawdust, wood shavings and the like.

In mills and factories making products from wood, there is inevitably a substantial amount of wood waste. The waste occurs in a variety of forms ranging from sawdust to log butts and the different forms of waste occur at various points throughout the factory or mill. Heretofore, wood waste has been a serious and expensive nuisance so that many wood mills have been forced to expend large sums in disposing of this waste, for example, by dumping it in nearby wood piles.

Wood waste burns readily but heretofore there has been no completely satisfactory incinerator or furnace in which wood could be etfeciently, safely and completely burned. Hand feeding of wood waste to a furnace or incinerator is extremely dangerous and automatic firing methods have, in general, been unsuitable for small chips and particles of Wood such as wood bark. In addition prior incinerators have been difiicult to install and dangerous to operate as well as difiicult to control so as to correlate the rate of burning with the rate at which the waste is formed or made available.

In my copending application Serial No. 481,097 filed January 11, 1955 now patent 3,022,753 issued February 27, 1962, I have disclosed a system in which wood chips and particles to be burned are conveyed on a stream of moving air to an incinerator or furnace wherein the incinerator also serves as a dust collector. The present invention provides an incinerator of the same general type asdisclosed in the aforesaid copending application but which is substantially improved in several respects.

Through the novel features of the incinerator of the present invention, I have found it possible to substantially increase the efiiciency of incinerators of this type so that the fuel is completely consumed and leaves substantially no ashes or residue upon burning. This increased efficiency of burning not only substantially eliminates ashes but assures that substantially no sparks will be emitted from the incinerator stack or chimney and the need for a spark arrestor in all except the most unusual circum stances is completely eliminated. Also provided by the improved incinerator of the present invention are novel means for trapping noncombustible dust or sand particles and separating these particles from the combustion fuel to automatically remove them from the combustion chamber of the incinerator so that the incinerator need not be periodically shut down in order to remove the collected clinker or glass from the incinerator bed.

It is therefore a primary object of the present invention to provide a novel incinerator for burning combustion fuels.

Another object of the present invention is to provide an improved incinerator for burning woody materials and particularly wood bark.

Another object of the present invention is to provide a novel incinerator for burning combustion materials having a substantially improved combustion efliciency.

Another object of the present invention is to provide a novel incinerator of increased efficiency for burning combustion particles having a large Water content.

Still another object of the present invention is to provide a novel combination incinerator and sand collector 3,l3,l33 Patented Dec. 29, 1%64 providing means for preventing sand from collecting at the bottom of the incinerator.

Another object of this invention is to provide a novel combination incinerator and sand collector including means for automatically removing the sand from the bottom of the combustion chamber.

These and further objects and advantages of the invention will be more apparent upon reference to the following specification, claims and appended drawings, wherein:

FIGURE 1 is a vertical cross section through a portion of the incinerator of the present invention, showing the inside of the combustion chamber;

FIGURE 2 is a cross section taken along line 2-2 of FIGURE 1;

FIGURE 3 is a plan view of the foundation layout of the incinerator of FIGURE 1;

FIGURE 4 is a cross section taken along the line 4-4 of FIGURE 3;

FIGURE 5 is an elevation of the novel sand trap of the present invention, incorporated in the incinerator of FIGURE 1; and

FIGURE 6 is a plan view of the novel sand trap of the present invention, incorporated in the incinerator of FIGURE 1.

FIGURE 7 shows an alternative arrangement for removing sand from an incinerator of the present invention involving auxiliary air feed means.

Referring to the drawings, FIGURE 1 shows the novel incinerator of the present invention generally indicated at 10, with parts broken away and parts in section, which incinerator while suitable for use in burning all types of fuel is particularly adapted for use in completely consuming wood bark waste from lumber mills. The incinerator ltl comprises an outer cylindrical wall 12 and a spaced inner cylindrical wall 14 forming a water jacket about a combustion chamber 16. Outer cylindrical wall 12 extends upwardly beyond the combustion chamber 16 to surround the lower portion of an exhaust stack 18. Communicating with the lower end of exhaust stack 18 and extending downwardly into the uppor portion of combustion chamber 16 is a short combustion outlet or chimney 2%.

An important feature of the present invention includes the provision of inner wall 14 surrounding combustion chamber 16 formed of a series of horizontal corrugations 22 which serve to not only strengthen the inner wall of the combustion chamber but also acts to greatly enhance the efiiciency of combustion in a manner more fully described below. The inner jacket 14 terminates in an integral upwardly angled annular cover or lid 24 forming the top of the combustion chamber. Cover 24 terminates short of and is spaced from chimney 20 to provide annular aperture 26 communicating with an inner annular water chamber 28 surrounding chimney 2th. The inner wall of chamber 28 is formed by the chimney 20, while the outer wall of this chamber is formed by a circular flange 30, extending downwardly from the inner edge of cover 24. As can be seen from FIGURE 1, water fills the space between inner and outer walls or shells 12 and 14 through a water inlet 33 to a height indicated at 32, approximately level with the lower end of exhaust stack 18. The water further fills the space between chimney 2i) and downwardly extending flange 3t? so that the entire length of chimney 20 is surrounded by two spaced Water jackets, the inner one defined by the chimney in conjunction with flange 3t and the outer one defined by the inner and outer cylindrical walls 12 and 14.

Communicating with the lower end of the annular water jacket or chamber 28 are a plurality of downwardly extending ribs or wings 34 preferably spaced, as best seen in FIGURE 2, an equal distance angularly about the center of the combustion chamber adjacent the entrance to the lower end of chimney 2% A passageway between annular chamber 30 and each of the wings 34 for the flow of water is provided by apertures 3d, spaced about the inwardly extending annular flange 38, closing oil the lower end of annular chamber 28. Each of the wings 34- may be provided with removable drain plugs 40, if so desired.

Extending downwardly from two of the Wings 34, prefera-bly spaced on opposite sides of the combustion chamber as indicated in FIGURES 1 and 2 are a pair of hollow arms 42 and 44, providing a water flow path to a hollow conical disc 46 depending from the extreme lower ends of the two arms 42 and 44.

The outer Wall 12 of the incinerator is provided with a tangential inlet 48 for admitting wood particles carried by a stream of moving air into the combustion chamber of the incinerator. An important feature of the present invention is the fact that the inlet fixture 48 is formed to provide a tangential inlet path for the flow of air and particles and is positioned adjacent the top of the combustion chamber.

Extending outwardly from one side of outer wall 12 is a rigid frame 50 comprising a downwardly sloping rib 52 and a horizontal rail Riding along rail 54 is a roller 56; secured by a suitable bracket 58 to one end of a vertical rod 60. The other end of rod 6%? is secured by means of a second similar bracket 62 to a pivot d4, formed in the top of the incinerator access door generally indicated at 66.

Water-jacketed door 66 is provided with a concave interior surface 68 conforming to a portion of the cylindrical inner surface of combustion chamber 16 with a major portion of the door being formed of fire clay, as indicated at '79. The door may be completely filled with water, with fire clay, or with separate sections of each. It is par cularly desirable to provide fire clay on the inside to protect the door from high temperatures and also to provide the smooth concave surface 63 so as to avoid turbulence caused by air going by either a cavity or a projection at that point.

A counter weight 72 extends outwardly from the door to balance the weight of the fire olay 7'9 and a suitable handle 'ld is provided on the front of the door for easy manipulation. The door may be closed and locked in place by means of suitable latches on either side, one of which is indicated at 75. Since the door is heavy and cumbersome it is preferred that it be suspended from frame 56 and carried along a rail 54 so that the operator has greater leeway in manipulating the door by means of the handle 74-. Bracket 5i may be rigidly supported from outer cylindrical wall 12 to provide ample support for the door and suitable additional reinforcements may be provided if desired.

The foundation of the incinerator It is illustrated in FIGURES 1 and 3 and is formed of an annular cement base, preferably recessed into the ground as indicated at 82 in FIGURE 4, with only the upwardly extending annular boss 34 visible above the surrace the earth. A plurality of bolts 86 are embedded in the cement base 851* and secured by suitable nuts to an outwardly extending annular flange, 96, formed about the lower end of outer wall 12. it is by means of the bolts 8:? that the entire incinerator structure is secured to the cement foundation 8% The interior or" foundation is provided with loose rock 92 in which are embedded a plurality of sections of vitrified clay ewcr pipe of circular cross section as seen; for example, at ifl-i in FIGURE 1. This vitrified clay or terra cot-ta pipe 94 is not joined together but spaced in the form of .a cross with small gaps between eaech section as indicated, for example, at in FIGURE 3. A suitable channel lid is provided in the upper portion 84 of the cement foundation to provide clearance for an outwardly extending section 1&2 of the pipe which may be connected by suitable means to an external air supply.

As seen in FIGURE. 4, the terra cotta pifirg is preferably surrounded by loose stone or brick as indicated at 134.

Resting on the top surface of loose rock are two layers of tire brick indicated at lilo, with the upper layer forming the bottom surface of the combustion chamber 15 of the incinerator. As best seen, for example, in FIGURE 4 the firebriclrs are laid with small spaces 1% in between and no mortar is used so that nay gain access from the underlying terra cotta pipe to the combustion chamber by passing through the spacing between the firebricks res.

A small stainless steel cone 119 may be positioned on the iioor of the combustion chamber in the ccnter of the incinerator. This cone may be provided with some very small apertures H2 so may flow through it from beneath.

Attached to the interior of corrugated inner wall la of the incinerator is a vertical plate 116 forming a portion of a sand trap generally indicated at 118 and shown in detail in FlGURlES 5 and 6. The outer edge 12b of plate lit; is preferably scalloped to mate with the corrugations forming the interior surface of inner jacket 14 and is secured by suitable means to the inner jacket. The extreme innermost edge of plate lie is turned over to form a short flange 12?. extending substantially parallel with a portion of the corrugated wall 14.

Fitted within the pocket or recess formed by flange 122 is the vertical edge of a sand screen 124. The opposite edge of the screen 124 rests in contact with and against the inner wall of the incinerator as indicated at no in FIGURE 5 and 6. The screen is thus held in position against the inner wall of the incine ator by the retaining action of flange 12?. acting along one edge of the screen. An integral top plate 123 extends along the upper edge of the screen and is provided with a clean out hole 325.

A small outlet aperture 128 is provided adjacent the bottom of plate 116, which aperture communicates with a small pipe 13% passing outwardly through the wall of the incinerator with. its outer end at B2 positioned adiacent the mouth a much larger pipe ill-=1. Pipe E32 passes through a suitable aperture E35 in the incinerator wall and is supported by a firebricl; 136.

In operation the wood bark "or other particles to be burned are conveyed on a suitable air stream in a well known mariner to the inlet 43 of tie incinerator ill. The air stream passing in through the tangential inlet sets up a tangential how of air and particles within the combustion chamber if: and the particles carried in the stream of air tend to gradually settle under the influence of gravity to the bottom of the incinerator. At the same time a suitable air source coupled to the terra cotta pipe 182 beneath the incinerator supplies a forced draft up through the terra cotta piping and tr e two layers of firebriclr LO provide additional air to the combustion chamber 16. Air after entering combustion chamber 15 passes around disc 46 and between wings 34 upwardly through chimney 2'59 and outwardly through exhaust stack 18 to the atmosphere. Although it is not ordinarily needed a suitable spa arres-tor in the form of a mesh screen may be fitted over the extreme top portion of stacl: 3, if desired.

An important feature of the present invention is the corrugated inner shell or Wall 14 surrounding the combustion chamber. In addition to the corrugations adding substantial strength to the inner wall to avoid collapsing of this wall it has further been discovered that in having the horizontal corrugations the burning particles in dropping by gravity through the combustion chamber are thrown outwardly by the centrifugal nature of the feed through the inlet 48 and tend to stay in the corrugations. This centrifugal action of the feed through pipe 48 tends to keep the material in a particular horizontal corrugation by centrifugal force so that the particles tend to stay in suspension in the combustion chamber for much greater periods of time resulting in an almost perfect suspension burning of the incoming materials. Without the corrugations on the inside surface of shell 14 the materials tend to reach the bottom of the incinerator in one to two revolutions whereas with the corrugations they go round and round time after time before descending to the bottom of the incinerator and are almost always completely burned before reaching the bottom.

Another important feature of the present invention is the placement of the terra cotta piping to provide the forced draft through the incinerator. The need for accessary air is occasioned by the desirability of preventing smothering of the fire with the resulting incomplete combustion. Conventional methods of applying forced draft to incinerators tend to cause turbulance in the combustion chamber that makes the incinerator throw out sparks, dust, and whatever else it contains from the top of the exhaust stack. In the preferred embodiment, the terra cotta pipe is an 8 inch pipe and the firebricks forming the fioorof the incinerator are spaced A inch apart without any mortar between the bricks. This gives a substantially smooth bottom to the incinerator, stops turbulance and eliminates any possibility of blowing particles out through the top of the incinerator.

Of special significance is the sand trap 118 for automatically removing sand from the combustion chamber. As a result of this trap, it is entirely unnecessary that the incinerator be periodically cooled down and emptied since the sand is automatically and continuously removed by the sand trap. Applicant has found that the incinerator functions most efiiciently if there is a bed of coals over the bottom surface of the combustion chamber. It has been further found that sand entering with the bark or other woody materials to be burned goes around within the combustion chamber almost like dust. While any suitable screen may be employed in conjunction with the sand trap, in the preferred embodiment the screen 122 is formed from Nichrome V wire having elongated horizontal slots 1 of an inch wide. This screen is capable of withstanding the extreme temperatures within the incinerator and removes the sand without also removing the finer particles of bark.

The pipe or duct 130, forming a portion of the sand trap is quite small and in one embodiment has outside dimensions of l and /2 inches by 6 inches. The outlet of this pipe or duct coming out of the incinerator goes into the mouth of pipe 134, which in the same incinerator has a 10 inch diameter. With the much larger suction pipe it was possible in the example given to dilute the extreme heat which may be in the order of 2500 degrees with something like eight parts of atmospheric air to one part of the combustion gases so as to avoid any tendency of burning up either the pipe or the dust collector to which the pipe 134 leads.

The water filled wings or deflectors 34 are positioned adjacent the outlets from the combustion chamber and act to break the whirling force of the outgoing gases so as to reduce the back pressure. The water jacket disc 46 is to prevent tornados from forming inside the incinerator. Without this disc, little tornados or whirlwinds tend-to form and in some instances reach down to the bottom or bed of coals. When the tops of the potential tornados are cut off with this disc they do not form.

As can be seen, the chimney 20 extending upwardly from the incinerator is much smaller in diameter than the subsequent exhaust stack is. The purpose of this, is to allow for expansion of the heated gases and to protect the non-jacketed exhaust stack from the intense heat. As an additional measure, air holes (not shown) can be provided at the bottom or close to the bottom of the large exhaust stack to let in fresh air so as to dilute the heat of the exhaust gases to protect the stack.

The purpose of the cone 110 at the bottom center of the incinerator is to prevent sand from accumulating in the middle of the incinerator where centrifugal force 6 could not in all instances be depended upon to remove the sand to the outside of the incinerator.

Outer shell 12 preferably extends a substantial distance up the sides of the incinerator beyond the water level 32 so that boiling and bubbling of the water does not cause it to spill over above the shell so as to drop down on any persons or apparatus along side of the incinerator. For this purpose the upper edges of shell 12 are turned over as indicated at 13, to help retain the water within the outer incinerator shell. If desired, suitable baflles may be additionally placed over the upper end or outer shell 12.

FIGURE 7 shows a modified incinerator employing an auxiliary air feed adjacent the floor of the combustion chamber 16. A large main air supply conduit supplies air under pressure to a plurality of tangential feed arms 142, 144, 146 and 148. These arms feed auxiliary air under pressure tangentially into the lower part or bottom of the incinerator just above the level of the floor.

Since it has been found that for optimum operation it is desirable to have a bed of coals at the bottom of the incinerator it is not ordiarily desirable to feed auxiliary combustion air by means of the tangential feed apparatus shown in FIGURE 7. However, when the incinerator is used for general waste disposal, a lot of non-combustible materials invariably enter the incinerator along with the combustible materials and collect at the bottom of the incinerator.

With the fire out, and the door open it is possible by using the auxiliary air supply system shown in FIGURE 7, in conjunction with the regular forced draft coming up from beneath the floor, to blow all sand, bark and noncombustible materials out of the door of the incinerator even though the door is placed several inches above the floor.

When it is contemplated that the incinerator is to be used for primarily burning materials with a large percentage of non-combustibles such as in cleaning out railway boxcars Where materials such as brick particles, rocks, nails, tramp iron, tile and the like may very well find their way into the incinerator, it is desirable to construct the incinerator with the bottom of the door slightly below the inside floor of the incinerator. In either case, when there is an accumulation of noncombustible materials on the floor ofthe incinerator, the procedure is to run the incinerator so that the combustibles are burned out, then the door is opened and the auxiliary fan supplying the auxiliary feed apparatus in FIGURE 7, is started to give the extra centrifugal force at the floor level. This will result in the blowing out of all tramp iron, rocks, bricks and other materials, in a few minutes without having to cool the incinerator down. This is in contra distinct-ion to the conventional procedure wherein the incinerator must be cooled down to the point that a man can get inside and lift these material out. By utilizing the auxiliary feed air supply arrangement of FIGURE 7, it is not necessary to cool the incinerator down since the non-combustibles are simply blown out the door. The door can then be closed and more combustibles blown into the incinerator, ignited and the burning process resumed. Although this auxiliary apparatus requires a brief shut down of the equipment there is a substantial savings in time and accompanying increase inefliciency resulting from the fact that the shut down time is short and that no substantial cooling down and reheating period is required.

It is apparent that the present invention provides a novel and substantially improved incinerator for burning all types of combustible products. Important features of the present invention include corrugated inner walls for increased suspension burning, as Well as a novel sand trapfor automatically clearing the bottom of the combustion chamber. Auxiliary air supply means may be provided for clearing heavy noncombustible materials from the bottom of the incinerator.

Because of the increased efiiciency of combustion provided by the various novel features of the present incineraltor, applicant has found that it is possible to burn up bark with a moisture content of as much as 50% without any noticeable change in operation. The incinerator gives a complete combustion in that it is never necessary to clean out any ashes. Ashes cannot be seen escaping from the top of the incinerator so it is presumed that they are bark burning boilers.

Other uses of the incinerator include the thermal debarking of logs. it has been found that by heating the camfbuimvlayer of frozen Wood to 180 F. the bark may be readily removed.

The invention may be embodied in other specific forms without departing from the pirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

' 1. An incinerator for burning particles of combustible material comprising a combustion chamber having spaced cylindrical inner and outer vertical side walls defining a water jacket, a top Wall for said chamber having an out let therein substantially concentric with said side walls and means for introducing the particles and air for combustion adjacent the top of said chamber and tangential to said inner side wall, said inner side wall being formed with a plurality of horizontal corrugations whereby particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber, a plurality of spaced vitrified clay pipe sections beneath said chamber, mean for connecting a forced draft air supply to said pipe sections, and means connecting said pipes for the flow of air with the interior of said combustion chamber.

2. An incinerator for burning particles of combustible material comprising a combustion chamber having spaced cylindrical inner and outer ventical side walls defining a water jacket, .a top wall for said chamber having an outlet therein ubstantially concentric with said side walls and means for introducing the particles and air for cornbustion adjacent the top of said chamber and tangential to said inner side wall, said inner side wall being formed with a plurality of horizontal corrugations whereby particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber, a plurality of spaced vitrified clay pipe sections beneath said chamber, means for connecting a forced draft air supply to said pipe sections, and means connecting said pipes for the flow of air with the interior of said combustion chamber, and a sand trap including a filter screen formed along said side wall adjacent the bottom of said chamber whereby particles ofsand pass through said screen into said trap under the influence of centrifugal forces set up in said chamber .by the tangential introduction of air adjacent the top of said chamber.

3. An incinerator according to claim 2 wherein said screen is a stainless'steel plate having narrow elongated horizontal slots approximately inch wide.

4. An incinerator for burning particles of combustible material comprising a combustion chamber having spaced cylindrical inner and outer side Walls defining a Water 8. jacket, a door in the side walls of said chamber, a top wall for said chamber having an outlet therein substantially concentric with said side Walls and means for introducing the particles and air for combustion adjacent the top of said chamber and tangential to said inner side wall, said inner side wall being formed with a plurality of horizontal corrugations whereby particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber, a plurality of spaced vitrified clay pipe sections beneath said chamber, means for connecting a forced draft air supply to said pipe sections, and means connecting said pipes for the flow of air with the interior of said combustion chamber, and a sand trap including a filter screen formed along said side Wall adjacent the bottom of said chamber whereby particle of sand pass through said screen into said trap under the influence of centrifugal forces set up in said chamber by the tangential introduction of air adjacent the top of said chamber and means adjacent the bottom of said chamber for introducing auxiliary air under pressure tangentially into said chamber whereby non-combustibles collected at the bottom of said chamber may be forced through said door by the centrifugal forces created by air passing through said auxiliary means.

5. An incinerator for burning particles of combustible material comprising: a combustion chamber having spaced inner and outer cylindrical side walls defiining a water jacket; means for introducing the particles and air for combustion adjacent the top of said chamber and tangential to said inner side wall; said inner side wall being formed with a plurality of horizontal corrugations so that particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber; a top wall for said chamber having an outlet substantially concentric with said side walls; a Water jacketed chimney connected to said outlet so that said outlet forms one end of said water jacketed chimney in the top of said combustion chamber; and a water jacketed disc positioned below said outlet for breaking up any whirlwinds tending to form in said chamber.

6. An incinerator for burning particles of combustible material comprising: a combustion chamber having spaced cylindrical inner and outer side walls defining a Water jacket; a top Wall for said chamber having an outlet therein substantially concentric with said side walls; a water jacketed chimney connected to said outlet and extending into said chamber; a stack of substantially larger cross section than said chimney connected to said chimney and extending away from said chamber; means for introducing the particles and air for combustion adjacent the top of said chamber and tangential to said inner side Wall; said inner side Wall being formed with a plurality of horizontal corrugations whereby particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber; a plurality of spaced vitrified clay pipe sections beneath said chamber; means for connecting a forced draft air supply to said pipe sections; means connecting said pipes for the flow of air with the interior of said combustion chamber; a sand trap including a filter screen formed along said-side wall adjacent the bottom of said chamber whereby particles of sand pass through said screen into said trap under the influence of centrifugal forces set up in said chamber by the tangential introduction of air adjacent the top of said chamber; a water jacketed disc positioned below said outlet for breaking up any Whirlwind ten-ding to form in said chamber; and said outlet forming the upper end of said chimney in the top of said combustion chamber and opening into said stack.

7. An incinerator for burning particles of combustible material comprising: a combustion chamber having spaced cylindrical inner and outer side walls defining a water jacket; a top wall for said chamber having an outlet therein substantially concentric with said side walls; a water jacketed chimney connected to said outlet and extending into said chamber; a stack of substantially larger cross section than said chimney connected to said chimney and extending away from said chamber; means for introducing the particles and air for combustion adjacent the top of said chamber and tangential to said inner side wall; said inner side wall being formed with a plurality of horizontal corrugations whereby particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamher; a plurality of spaced vitrified clay pipe sections beneath said chamber; means for connecting a forced draft air supply to said pipe sections; means connecting said pipes for the flow of air with the interior of said combustion chamber; a sandtrap including a filter screen formed along said side wall adjacent the bottom of said chamber whereby particles of sand pass through said screen into said trap under the influence of centrifugal forces set up in said chamber by the tangential introduction of air adjacent the top of said chamber; a water jacketed disc positioned below said outlet for breaking up any whirlwind tending to form in said chamber; said outlet forming the upper end of said chimney in the top of said combustion chamber and opening into said stack; and a plurality of circularly spaced vertically extending water filled wings positioned between said chimney and disc.

8. An incinerator for burning particles of combustible material comprising; a substantially cylindrical combustion chamber; at least one layer of spaced fire bricks forming the floor of said combustion chamber; means for introducing the particles and air for combustion into said chamber tangential to the inner side wall thereof; a plurality of spaced pipe sections beneath said chamber; means for connecting a forced draft air supply to said pipe sections; means connecting said pipes for the flow of air with the interior of said combustion chamber; and said pipes being in a form of a cross and communicating with the interior of said chamber through said fire-bricks.

9. An incinerator for burning particles of combustible material comprising: a combustion chamber having spaced cylindrical inner and outer vertical side walls defining a water jacket; a top wall for said chamber having an outlet therein substantially concentric with said side walls; a bottom wall having a plurality of spaced openings; means for introducing the particles and air for combustion into said chamber tangential to said inner side wall; said inner side wall being formed with a plurality of horizontal corrugations located below said means for introducing the particles and air for combustion into said chamber so that particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to said bottom wall; and means for connecting a forced draft air supply to said chamber through said openings in said bottom wall.

10. An incinerator for burning particles of combustible material comprising: a substantially vertical cylindrical combustion chamber; means for introducing the particles and air for combustion into said chamber tangential to the inner side wall of said chamber; said inner side wall being formed with a plurality of horizontal corrugations located below said means for introducing the particles and air for combustion into said chamber so that particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber; and a sand trap including a filter screen formed along said inner side wall adjacent the bottom of said chamber so that particles of sand pass through said screen into said trap under the influence of 10 centrifugal forces set up in said chamber by the tangential introduction of'air into said chamber.

11. An incinerator for burning particles of combustible material comprising: a substantially vertical cylindrical combustion chamber; means for introducing the particles and air for combustion into said chamber tangential to the inner side wall of said chamber; said inner side wall being formed with a plurality of horizontal corrugations located below said means for introducing the particles and air for combustion into said chamber so that particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber; a sand trap including a filter screen formed along said inner side wall adjacent the bottom of said chamber so that particles of sand pass through said screen into said trap under the influence of centrifugal forces set up in said chamber by the tangential introduction of air into said chamber; and said screen having its side adjacent to said inner side Wall formed with a pluralty of horizontal corrugations.

12. An incinerator for burning particles of'combustible material comprising: a substantially vertical cylindrical combustion chamber; means for introducing the particles and air for combustion into said chamber tangential to the inner side wall of said chamber; said inner side wall being formed with a plurality of horizontal corrugations located below said means for introducing the particles and air for combustion into said chamber so that particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber; a sand trap including a filter screen formed along said inner side Wall adjacent the bottom of said chamber so that particles of sand pass through said screen into said trap under the influence of centrifugal forces set up in said chamber by the tangential introduction of air into said chamber; and said screen being made of nichrome V wire and having a plurality of narrow elongated horizontal slots.

13. An incinerator for burning particles of combustible material comprising: a substantially vertical cylindrical combustion chamber; means for introducing the particles and air for combustion into siad chamber tangential to the inner side wall of said chamber; said inner side wall being formed with a plurality of horizontal corrugations located below said means for introducing the particles and air for combustion into said chamber so that particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber; a sand trap including a filter screen formed along said inner side wall adjacent the bot tom of said chamber so that particles of sand pass through said screen into said trap under the influence of centrifugal forces set up in said chamber by the tangential introduction of air into said chamber; and said trap including a relatively small pipe communicating with the open end of a larger pipe immediately outside said chamber and directly communicating with ambient temperature air so that the hot air passing through said small pipe is diluted by ambient air upon entering said larger pipe.

14-. An incinerator for burning particles or combustible material comprising: a vertical combustion chamber; means for introducing the particles and air for combustion into saidchamber tangential to the inner side wall of said chamber; said inner side wall being formed with a plurality of horizontal corrugations located below said means for introducing the particles and air for combustion into said chamber so that particles carried by a stream of air entering said chamber tend to be retained in suspension in said corrugations for substantial periods before falling under the influence of gravity to the bottom of said chamber; a door adjacent the bottom of said chamber; and means adjacent the bottom of said chamber for in- References Cited in the file of this patent UNITED STATES PATENTS Nu ssbaum Jan. 23, 1900 Due Aug. 19, 1902 Crothers June 3, 1930 Lauterbur et a1 Dec. 13, 1932 Snow et a1 Jan. 17, 1933 Johnson et a1 May 5, 1936 Sturges Feb. 9, 1937 Badenhausen Dec. 5, 1944 Glaeser Oct. 4, 1949 Batter Sept. 26, 1950 Iefieries Oct. 31, 1950 Baier Aug. 5, 1952 J'ukkoia May 19, 1953 Van Loon May 3, 1955 Birkner Ian. 17, 1956 Hartley et a1 May 8, 195

Triggs June 5, 1956 FOREIGN PATENTS Great Britain June 27, 1956 

9. AN INCINERATOR FOR BURNING PARTICLES OF COMBUSTIBLE MATERIAL COMPRISING: A COMBUSTION CHAMBER HAVING AN OUTLET CYLINDRICAL INNER AND OUTER VERTICAL SIDE WALLS DEFINING A WATER JACKET; A TOP WALL FOR SAID CHAMBER HAVING AN OUTLET THEREIN SUBSTANTIALLY CONCENTRIC WITH SAID SIDE WALLS; A BOTTOM WALL HAVING A PLURALITY OF SPACED OPENINGS; MEANS FOR INTRODUCING THE PARTICLES AND AIR FOR COMBUSTION INTO SAID CHAMBER TANGENTIAL TO SAID INNER SIDE WALL; SAID INNER SIDE WALL BEING FORMED WITH A PLURALITY OF HORIZONTAL CORRUGATIONS LOCATED BELOW SAID MEANS FOR INTRODUCING THE PARTICLES AND AIR FOR COMBUSTION INTO SAID CHAMBER SO THAT PARTICLES CARRIED BY A STREAM OF AIR ENTERING SAID CHAMBER TEND TO BE RETAINED IN SUSPENSION IN SAID CORRUGATIONS FOR SUBSTANTIAL PERIODS BEFORE FALLING UNDER THE INFLUENCE OF GRAVITY TO SAID BOTTOM WALL; AND MEANS FOR CONNECTING A FORCED DRAFT AIR SUPPLY TO SAID CHAMBER THROUGH SAID OPENINGS IN SAID BOTTOM WALL. 